Last played singleplayer world changes date last opened to 1/1/70

I too can confirm this on a windows 7 machine. My on board time is correct. Was in a creative world.

I thought they were getting deleted, I was relieved when i tried to paste my back up (missing a large chunk of work i had just been doing) into the saves folder and it said it was already there.

Confirmed for 13w24b. It's annoying to have your most recently played worldsaves at the bottom of the list!

Coincidentally or not, that is the date of the Unix Epoch. Hmm...

http://en.wikipedia.org/wiki/Unix_Epoch

At first, I didn't know where all the worlds went!

@Nathan R: There is literally no way whatsoever that that is a coincidence.

Now mine says 12/31/1969 for some of them – see attached screenshot

I've also seen this issue. One odd thing is that the time is 12 hours off. Attached a screen shot showing this. Im using: Windows 7 64-bit, Java 7 64-bit and Swedish regional settings.

Confirmed on Linux 64-bit using "OpenJDK Runtime Environment (IcedTea 2.3.9) (7u21-2.3.9-1ubuntu1)"

Yes! Another Linux user!!

Nathan R: the begin of 1970 is also the epoch for java's time when it uses long-value of milliseconds. The reason why Windows ends up showing e.g. last day in 1969 might have something to do with timezones/daylight savings stuff etc., where Linux offers slightly more (and different) options than Windows.